1. Field of the Invention
The present invention relates generally to systems for providing operational flight phase indications and more particularly to a system for determining and indicating the flight phase utilizing aircraft sensors, airplane automation modes, and flight crew input.
2. Description of the Related Art
Some avionics functions are dependent on the aircraft's phase of flight. For example, on-board data load is disabled when the aircraft is in-air. A slightly more complex example is the on-board weather radar, which uses a variety of inputs to determine takeoff and landing mode in order to automatically enable the predictive windshear detection function.
Generally today's avionics functions do not determine operational flight phase, but rather determine equipment operating modes using one or more aircraft state inputs and pilot commands to drive pre-defined logic determined at design time. Such methods are not able to account for all the real-time conditions that affect flight phase determination and they are not able to account for the operational intent of the pilot. In addition, current implementations are often federated, meaning each function uses its own inputs and logic, which can lead to flight phase disagreement between systems.
The limitations of the current methods will be a hindrance to the introduction of new flight deck automation, which have increased dependency on the unambiguous and consistent determination of the operational flight phase. Examples of this are Automatic Dependent Surveillance-Broadcast (ADS-B) In applications such as Airport Surface Situation Awareness and the on-board decision aids needed in NextGen mid- and far-term concepts being defined by the Federal Aviation Administration.
Flight mode annunciator systems are commonly used with today's flight management and autoflight systems. These are based on various devices. For example, U.S. Pat. No. 6,892,118, issued to T. L. Feyereisen, entitled Pictographic Mode Awareness Display for Aircraft, discloses a device, method and computer program for generating and displaying graphical displays symbolic of current and available operational modes of instrument systems, such as navigation and autopilot systems. The Feyereisen method includes receiving a signal representative of a current mode of operation of one or more instrument systems, interpreting the current mode of operation signal to determine the current mode of operation, outputting a control signal informing a pictographic representation symbolic of the current mode of operation, and displaying the pictographic representation of the current mode of operation on a display device, such as a cockpit panel display.
An operational flight phase may be defined as the current operational purpose of the flight or ground segment, usually from the perspective of the pilot or operator. Typical operational phases, part of nearly every flight segment, are Pre-flight, Engine Taxi Out, Take-off, Climb-out, Cruise, Descent, Approach, Landing, Taxi-In, Engine Shut-Down, and Post-flight. Additional operational modes can be defined for emergency events or optional operational activities such as de-ice, return-to-service engine checks, ferry flights, etc. It is noted that these operational flight phases are distinct from the avionics system automation modes typically found in flight management systems and autopilot systems. Such systems may define modes such as “altitude hold” or “lateral navigation”, however, these modes refer to the mode of the flight management or autopilot system, not the operational intent of the pilot. For example, an autopilot may be commanded by the pilot to a “heading hold” mode to keep the airplane on a pre-determined heading. The autopilot does not ‘know’ the operational intent of the heading hold mode, which could, for example, be to assist with following air traffic control vectors during final approach, or may be to follow a specific heading direction during cruise flight. As noted above, generally today's avionics functions do not determine the operational phase of flight, but rather they determine equipment mode using one or more aircraft state inputs and/or pilot inputs to drive pre-defined logic determined at design time. Such methods are not able to account for all the real-time conditions that affect flight phase determination. In addition, current implementations are often federated, meaning each function uses its own inputs and logic, which can lead to mode disagreement between systems.
Operator procedures are often based on the operational flight phase. For example, during Pre-flight the flight crew checks the operational status of aircraft systems and configures those systems for the intended operation. In many cases the operational flight phase determines how the aircraft systems are used. For example, when in the takeoff operational flight phase, the parking brake is not set while the engines are brought up to takeoff thrust. However, when performing a return-to-service engine check, the parking brake must be set while the engines are brought up to high thrust.
A deficiency in today's avionics systems is that the system modes as defined by the current state of the art do not take into account the operational flight phase and do not modify their operation based on the operational flight phase. This means the pilot must understand how the intended flight operation affects the overall system operation and command the avionics systems to the proper configuration.
This places a burden on the pilot to understand the objectives of the intended operational flight phase and configure the aircraft systems appropriately. This imposes additional workload on the pilot and in some cases has led to accidents such as unintentional aircraft movement during return-to-service engine checks.
The aforementioned prior art focuses on the modes of the on-board systems. Additionally, the prior art does not address the effect of the higher level operational flight phases on the on-board systems and the high workload placed on the pilot to properly configure the on-board systems appropriately for the intended operation.